Games like The Midnight 21
Games like The Midnight 21 include Balatro, UNO, Blue Prince, Demonic Mahjong, and Bloons TD 6. We matched them by the tags players give The Midnight 21 on Steam (Casual, Strategy, Card Game, Time Management, and 3D): closest matches first, and among equally close ones the better-known games.

Balatro
Shared: Card Game · Strategy · Casual

UNO
Shared: Card Game · Casual · Strategy

Blue Prince
Shared: Mystery · Investigation · First-Person

Demonic Mahjong
Shared: Strategy · Card Game · Casual

Bloons TD 6
Shared: Strategy · Casual · 3D

Liars Bar
Shared: Casual · 3D · First-Person

Just Go
Shared: Casual · Strategy · Card Game

Sultan's Game
Shared: Strategy · Card Game · Time Management

Firewatch
Shared: Atmospheric · First-Person · Mystery

DICEOMANCER
Shared: Strategy · Card Game · Casual

The Room
Shared: Mystery · Atmospheric · Casual

Plague Inc: Evolved
Shared: Strategy · Casual · Indie

Buckshot Roulette
Shared: Strategy · First-Person · 3D

Moncage
Shared: Casual · Indie · Atmospheric

Rento Fortune: Online Dice Board Game (大富翁)
Shared: Casual · Strategy · Card Game

Papa's Freezeria Deluxe
Shared: Casual · Time Management · Strategy

Town of Salem
Shared: Strategy · Casual · Mystery

Clue/Cluedo: Classic Edition
Shared: Strategy · Casual · Mystery

Bogos Binted?
Shared: Casual · Strategy · Card Game

Wingspan
Shared: Card Game · Strategy · Casual

Retirement Simulator
Shared: Casual · Card Game · Strategy

Poker Night at the Inventory
Shared: Casual · Card Game · 3D

Among Us 3D
Shared: Strategy · Casual · 3D

Boxes: Lost Fragments
Shared: Casual · Mystery · 3D